DE3844364C2 - Method for controlling the light emission of a headlight arrangement of a vehicle and headlight arrangement for carrying out the method - Google Patents

Description

The invention relates to a method for controlling the light emission of a Headlight arrangement of a vehicle according to the preamble of claim 1 and a headlight arrangement for performing the method of the type of claim 8.

Such a method and such a headlamp arrangement is characterized by the DE-OS 21 56 535 known. In the procedure according to this document, the Light emission of a headlight controlled by at least one light sensor. The light sensor detects those acting on the driver of the vehicle Light emission from the driver's field of vision in the direction of travel of the Vehicle at least in an area of the field of view in which light sources can occur that are assigned to the opposite lane. Through the sensor the light intensity is detected and compared with a threshold value and if the threshold is exceeded, the light emission and / or the Light distribution of the headlight arrangement changed. The light emission and / or the light distribution of the headlight arrangement becomes such changed that from the headlamp assembly to the area where one Light source is arranged, the light of which is detected by the light sensor, no Light is emitted. Through this process, a glare of the Drivers of oncoming vehicles avoided, but visibility for the driver of the vehicle equipped with the headlight arrangement are not improved. Because the opposite lane is no longer illuminated the visibility for the driver of the with the Headlight arrangement equipped vehicle rather worsened because So-called black holes arise in the driver's field of vision and the light oncoming vehicles with the driver leads to increased glare.

DE-OS 21 44 197 is also a method for controlling the Light emission of a headlight assembly of a vehicle known in the essentially how the known method described above works and therefore also has the disadvantage described above.  

In addition, DE 28 03 777 A1 describes a method for controlling the Light emission of a headlamp arrangement is known, in which also the Light emission is controlled by at least one light sensor. Doing so depending on the light detected by the sensor from the headlamp assembly in the direction of the light emission emitted by the sensor weakened while the remaining light emission from the headlamp assembly should remain undiminished. This makes the driver more dazzling Prevents visibility for the driver of the vehicle vehicle equipped with the headlight arrangement, however, are not improved, but on the contrary, as already explained above, rather deteriorates.

The invention has for its object the visibility for one Driver encountering another vehicle while still on To improve headlights.

This task is characterized by the features Claim 1 solved.

The driver increases the Illumination of your own road side in the direction of travel by the headlight arrangement that of the headlights of the oncoming vehicle emitted light is perceived as less distracting than dazzling.  

With the increased lighting level, the driver's eyesight is reduced performance achieved in normal light without vehicle encounter Has. The increase in the light emission of the Vehicle controlled automatically, and that when the light inks a certain amount or light emission in the driver's field of vision Has reached the threshold value. This threshold can be optimized. The introduction of such a threshold value has the advantage that the Increasing the light emission of the headlamp not too early or too occurs late. If the increase occurs too early, it will be closed early adaptation to the higher light emission, so that part of the initial gain in visual performance is lost again. The Ef effect of visual impairment due to glare from the Headlights of the vehicle encountered, however, are not significantly reduced.  

Advantageous developments of the counter are in the subclaims status of the main claim. When designing according to an saying 2 advantageously results in a reduced glare of the vehicle rers of the vehicle when light in certain areas of vision field of the driver has too high an intensity. this concerns especially the reflection of one's own headlight on right reflecting surfaces such as traffic signs or smoke screens.

With the claims 8 to 17 advantageous developments are ge give as a headlight arrangement to carry out the method of preceding claims. This results in the arrangement according to Claim 9 an advantageous evaluation of the received from the light sensor light to control the headlamp. With the subject of Claim 9 can be a very fast-working evaluation unit implement, the received signals by the shortest route to an adjustment or switching device for the light emission of the Headlights can be switched through. When designing according to An saying 10 results in particular an inexpensive switch direction with little sensor effort. With continuing education according to claim 13, the system is switchable when needed, while in the development according to claim 14 advantageously too high switching frequency is avoided.

drawing

Embodiments of the invention are shown in the drawing and are explained in more detail in the following description. It demonstrate:

Fig. 1 is a schematic of a Scheinwerferan order for performing the method according to the invention,

Fig. 2 shows the structure of a first embodiment of a light sensor to he replaced by the light emission from the field of view of the driver of the equipped vehicle headlamp assembly, wherein a light-receiving field is limited by a diaphragm,

Fig. 3 shows a second embodiment of the light sensor, wherein the light received de field is formed by a plurality of individual light-sensitive elements,

Fig. 4 shows a third embodiment, in a modification to the off operation example according to FIG. 3,

Fig. 5 shows a fourth Ausführungsbei play with a single light-sensitive element to which the field of view is imaged by a light deflecting device in quick succession with the aid of a scanning method,

Shows a representation of the division are mapped of the driver's field of view in ver different light-emitting fields which receiving a corresponding light field of the light sensor. 6,

Fig. 7 is a basic electrical circuit for evaluating the light sensor signal output and

Fig. 8 is a schematic diagram for changing the light emission of the headlamp assembly.

Description of the embodiments

In a motor vehicle not shown, a light sensor 1 is arranged on the front side, oriented in the direction of travel and detects the field of vision of the driver of the vehicle. The light sensor consists of an imaging optics 2 , one or more photosensitive elements 3 , which form a light-receiving field 4, are connected in the imaging level. The light-sensitive elements emit control signals via their signal output 6 to an evaluation circuit 7 , the output 8 of which is connected to a switching device 9 , via which the light emission or light distribution of a headlight 11 is controlled. This headlamp can either be an additional headlamp that can be switched on or off in support of a low-beam headlamp, or a modified headlamp or low-beam headlamp that is part of the standard equipment of the vehicle can be controlled so that its light emission takes place in the desired manner. The headlamp should increase the light emission in the direction of its own lane 22 ( FIG. 6) as encounter light when a light source occurs on the oncoming lane or reduce the light emission if too high a light emission occurs from certain areas of the driver's field of vision, as follows is explained in more detail. The evaluation circuit consists in principle of an amplifier 12 , which amplifies the signals coming from the signal output 6 and supplies a threshold switch 14 , to which a threshold transmitter 15 is assigned. The output of the threshold switch controls a power transistor 16 or another switching element via which a power circuit can be controlled. Preferably, the power transistor 16 controls the switching device 9 , which can consist, for example, of a relay 17 which controls the power supply circuit of a spotlight 11 in the sense of switching on or off. Alternatively, the switching device 9 can be used to control an adjusting device for the headlight setting or an additional light source in the headlight or a dimming device of the headlight.

To understand the device described above, a field of view of the driver of the vehicle according to FIG. 6 must also be taken into account. It can be seen there that the field of view is divided into three light-emitting fields, a first light-emitting field 18 , a second light-emitting field 19 and a third light-emitting field 20 . The first light-emitting field 18 includes the directional lane 22 of the vehicle, which has already been designated as its own lane, and which is equipped with the headlamp arrangement according to the invention, the adjacent lane edge 23 and up to a certain amount lying above the directional lane 22 or lane edge 23 Area 24 . The second light-emitting field 19 comprises the oncoming lane 25 and its adjacent lane edge 26 and an area 27 also lying above it. Finally, the third light-emitting field 20 lies above the regions 24 and 27 of the first and second light-emitting fields and comprises light sources which are above a certain height or a certain angle above the roadway. In the area of the third light field 20 , light emissions occur which can originate from high-lying light sources, from light reflections on bridge structures or from light reflections from fog walls.

Due to the configuration of the light sensor of FIG. 1 with the imaging optical system 2 and the photosensitive member 3, the light abstrah lumbar fields on the light receiving zone 4 and ready bezüg Lich the light emission evaluated. The light emission of the light from the radiating field is fed to the amplifier 12 as a signal, compared with an adjustable threshold value in the threshold switch 14 , which controls the power transistor 16 or the switching device 9 depending on whether the threshold value is exceeded or not reached. The threshold value can be set individually or it can also be carried out automatically according to a general light level, driving speed or other parameters influencing visual performance. The device works in such a way that when the signal level corresponding to the light from the second light-emitting field 19 exceeds the input threshold value, the threshold value switch switches on the headlight 11 as encounter light via the switching device 9 or increases the light emission of the vehicle in the direction of its own directional lane 22 . On the other hand, if the light emission of the first light-emitting field 18 and / or the third light-emitting field 20 exceeds its predetermined threshold value, the encounter light, the headlamp 11 or a correspondingly designed device is switched off with the aim of reducing the illumination of one's own directional path 22 . This is particularly true if the vehicle's own directional roadway 22 is illuminated too strongly by increasing the light emission and the given visibility, or if the driver can be blinded too much due to the increased light emission when hitting reflective surfaces. This occurs particularly when fog is formed. To evaluate the light emissions from the light-emitting fields, these are transferred to the light sensor 1 in such a way that the light-emitting fields can be selectively evaluated in the desired manner either with the aid of imaging optics or by appropriately designed light-receiving fields 4 .

A first embodiment of the light sensor is shown in FIG. 2. There, an imaging optical system 2 is schematically illustrated in the form of a converging lens, the converging lens is a further tet nachgeschal 29, in turn, the received light via the optical system 2 leads to a photosensitive member. 3 The corresponding light-emitting field can be imaged in the driver's field of vision via one of the wide ren lens 29 upstream, the light-receiving field 4 forming aperture 30 . The light-sensitive element 3 , which is now assigned to a specific light-emitting field, detects the total light emission of the light-emitting field, forms an output signal corresponding to this light emission, which in turn is queried in the evaluation circuit 7 for exceeding or falling below a threshold value and is processed as described above. Such a sensor can be assigned to the individual light-emitting fields.

In further to Fig. 2, 3, a light sensor can be determined by Fig. Also so-Stalten that turn the light from radiating fields are mapped onto an array 32 of multiple lichtemp-sensitive elements via the imaging optical system 2. In this case, arranged in order to individual light-sensitive elements 33 , one or more of which are each assigned to one of the light-emitting fields 18 , 19 , 20 . The output signals of these individual light-sensitive elements are evaluated individually or, in the case of several, per field, by the evaluation circuit. In this case, a single evaluation circuit can be provided for the entire arrangement 32 of light-sensitive elements if the light-sensitive elements 33 assigned in each case to individual light-emitting fields are evaluated in rapid succession. The headlight 11 is then switched in accordance with the evaluation result.

Fig. 4 shows a modification of the embodiment of FIG. 3 with individual light-sensitive elements 33 also arranged in series or in the light-emitting fields according to the areas formed, each of which collecting optics 34 are connected upstream. Through these preferably cylindrical lenses of the collecting optics 34 , the light-sensitive individual elements 33 can be assigned exactly to the light-emitting fields.

If one wishes to an increased effort for photosensitive members, in particular according to Fig. Reduce 4, one can according to an embodiment of FIG. 5 with a single photosensitive element 36 along, if one vorschaltet a correspondingly transformed optic this element and out downstream of a respective evaluation circuit.

In FIG. 5, as in the previous figures, an imaging optical system 2 is provided, which is followed by an oscillating mirror 37 . The oscillating mirror is moved back and forth in regular amplitude by a drive 38 and scans different areas of the field of vision of the driver of the vehicle via the imaging optics and images them in each case via a downstream converging lens 39 onto the light-sensitive element 36 . Accordingly, all parts of the field of view, in particular the light-emitting fields 18 and 19, are shown alternately on this. The output signal of the light-sensitive element 36 is synchronized with the movement of the oscillating mirror, sequentially scanned and evaluated via a threshold switch, which in turn controls the encounter light or the headlamp 11 in the aforementioned manner. The evaluation circuits of the above exemplary embodiments can contain a comparison device, the threshold switch 14 , which operate with the same threshold values assigned to all light-emitting fields or with different threshold values. In the latter case, it is avoided that an excessive switching of the backlighting occurs under unfavorable visibility conditions. To avoid switching in the special case when due to the increased light emission towards the first light-emitting field on the roadside reflection surfaces occur, which can temporarily increase the light emission from this light-emitting field 18 in the area where such reflections can occur, for. B. with reflecting traffic signs or traffic signs, the light-receiving fields 4 or the light-sensitive elements 33 there get a cover corresponding to the hatched area 40 in FIG. 6. In this way, light emissions from this area do not contribute to controlling the encounter light. If the light sensor consists of a large number of light-sensitive elements, light-sensitive elements can be excluded in this area.

FIG. 7 shows an evaluation circuit 107 , each with a sensor 1 a, 1 b and 1 c assigned to one of the light-emitting fields 18 , 19 , 20 , to which an amplifier 12 a, 12 b and 12 c is connected, which again follow threshold switches 14 a, 14 b and 14 c. The output of the respective threshold switches leads to switches 16 a, 16 b and 16 c, which are each assigned to the light sensors 1 a to 1 c and are connected in series in a power supply line 42 . The power supply line 42 leads to the switching device 9 , via which the headlight 11 or the encounter light is switched. In addition to the switches, a further switch 43 is inserted into the power supply line 42 and is controlled by a switching device 44 which can be actuated arbitrarily by the driver of the vehicle.

This evaluation circuit permits an evaluation of the light emission emanating from the light emitting fields and if a threshold value is exceeded or fallen below, this fact can be given priority over the conditions in the area of the other light-emitting surfaces, in that the encounter light then turns on or off. is switched off. It is the light sensor 1 a z. B. the first light-emitting field 18 , the light sensor 1 b assigned to the second light-emitting field 19 and the light sensor 1 c to the third light-emitting field 20 . Depending on the switching logic of the switching input device 9 can then the conditions are such that when the first and third light-emitting panel 18, 20 associated thresholds are not exceeded, the appropriate switches are closed and 16 b to C 16. Then the threshold value of the second light-emitting array 19 is exceeded, in accordance with laid-out switches or threshold value, so that the switching device is driven so then at also closed switch 43, that the meeting light 11 is turned on and the switch 16 b is closed. If the threshold value associated with the second light radiating from box 19 back below, the switch 16 opens b, the relay of the switching device 9 drops and the meeting light is switched off again. The same process occurs when the threshold value assigned to the first light-emitting field 18 or the third light-emitting field 20 is exceeded. Then the switches 16 a and 16 c open and the circuit is also interrupted. By actuating the switching device 44 , the encounter light can also be switched off via the switch 43 .

In addition to this configuration, in order to avoid too frequent switching back and forth when driving through the predetermined threshold values, an additional device can be provided with a current flow detection sensor 46 , which, for. B. designed as an inductive coil detects a current flow in the power supply line 42 and a timer 47 controlled by this. The timer is in egg ner parallel to the switches 16 a to 16 c and 43 lying Stromlei device 48 which dissipates from a current source or voltage source via which the rest of the headlight system 49 is switched. As soon as the current flow detection device 46 detects a current flow, the power line 48 is connected to the switching device 9 via the time switch, so that the switching device 9 remains activated for the duration of the time specified in the time switch, regardless of the position of the switches 16 a to 16 c or 43 . Only after the specified time has elapsed is the connection of the power line 48 to the switching device 9 interrupted again and controlled according to the positions of the aforementioned switches.

In an alternative embodiment, an evaluation circuit can be designed in such a way that, in the case of sensor configurations according to FIGS . 3 or 4, the individual light-sensitive elements 33 are queried in quick succession and at a predetermined frequency and compared with a predetermined or alternatively switchable threshold value and the comparison result in each case in a memory is stored, which memory is then queried for the maximum value, which in turn is determining for the switching of the encounter light. The evaluation is therefore carried out using multiplex technology. In another embodiment, the individual photosensitive elements according to FIG. 3 or 4 can be queried simultaneously via analog gates to maximum values, the respective maximum value then determining the switching of the switching device or the switching on or off of the encounter light.

Such a device is shown schematically in FIG. 8 with an imaging optics 2 , with an arrangement 32 of a plurality of light-sensitive elements 33 and a threshold value device 50 , via which a maximum value 51 , which exceeds the threshold value 52 , is detected and accordingly the switching device 9 is controlled. Through the switching device 9 , a servomotor 54 can now be switched, by means of which an aperture 55 is adjusted, which engages in the beam passage 56 of an encounter light 57 . The encounter light headlamp has a light source 58 , which is then always switched on, together with the rest of the headlamp system and a reflector 59 with a downstream lens 60 through which the edge 61 of the aperture 55 is imaged on the road or on the driver's field of vision. This aperture is one that generates a vertical light / dark boundary in such a way that only its own directional roadway 22 can be illuminated. Basically, the light distribution of the light emission of the headlamp can be changed, and in particular the change can be made so that in the direction 62 from which a signal exceeding a certain threshold value is derived, a lot of light and in a predetermined other range of directions little or no Light is emitted. In Fig. 8, an alternative is shown by which instead of the aperture 55, the light source 58 is shifted with the aid of a servo motor 63 , so that the location of the highest light intensity 64 of the light emitted by the headlight system on the own directional road 22 of the vehicle in Field of view 65 limited.

The above measures advantageously increase the lighting intensity of one's own directional lane 22 in the area of the first light-emitting field 18 when an increased light level occurs on the opposite lane, in order to improve the visual performance of the driver of the vehicle or the lighting contrast between oncoming light and the illuminated one to reduce own lane 22 . However, if the light emission from the first light-emitting field 18 is too high, which can be caused by reflective surfaces, reflective road surfaces or environmental conditions such as fog walls, the encounter light is switched off. For such cases, a further field 20 , which emits the third light, is provided, via which the encounter light is controlled in the same way.

Claims (13)

1. Method for controlling the light emission of a headlight arrangement of a vehicle with a headlight ( 11 ), the light emission of which is controlled by at least one light sensor ( 1 ) that detects the light emission acting on the driver of the vehicle from the field of view ( 65, 18, 19, 20 ) of the driver in the direction of travel is detected at least in the area of the field of vision in which light sources can be assigned to the oncoming lane, and the light intensity is compared with a threshold value and the light emission and / or the light distribution of the headlamp arrangement is changed if the threshold value is exceeded , characterized in that when the threshold value is exceeded, the light emission and / or the light distribution of the headlight arrangement is increased in order to increase the illumination of the vehicle's own roadway side in the direction of travel thereof. 2. The method according to claim 1, characterized records that the increase in light emission or the change the light distribution for a predetermined minimum period of time after threshold is exceeded. 3. The method according to claim 2, characterized in that that to change the light emission or Lichtver division of the headlight arrangement a headlight on or off is switchable. 4. Headlamp assembly for performing the method according to one or more of the preceding claims with a with an upstream optics ( 2 ) provided light sensor ( 1 ) on the front of the vehicle, which optics points in the direction of the field of vision of the driver of the vehicle, with a control device , which is connected to the output ( 6 ) of the light sensor ( 1 ) and with a device for changing the light emission of a headlamp of the headlamp, characterized in that the light sensor ( 1 ) has at least a light-receiving field ( 4 ) the field ( 18, 19, 20 ) of the field of view can be imaged via the optics ( 2 ). 5. Headlamp arrangement according to claim 4, characterized in that several, different areas of the field of view associated light sensors ( 1 , 1 a, 1 b, 1 c) or groups of light sensors ( 32 ) are provided, which are assigned to different areas of the field of view, and the light sensors or groups of light sensors are successively each connected to an evaluation circuit ( 7 ) of a control device which has a comparison device ( 14 ) which on the one hand has a threshold value transmitter ( 15 ) for a light emission value and on the other hand to the light sensor ( 1 , 1 a , 1 b, 1 c) or the light sensor group ( 32 ) is connected and the output values of which are connected via a signal memory and in particular via a logic logic circuit to an actuating or switching device ( 9 , 54 , 63 ) through which the light emission of a Headlamp of the headlamp assembly is increased. 6. Headlamp arrangement according to claim 4, characterized in that a plurality of light sensors or a light sensor with groups ( 32 ) of light-sensitive elements ( 33 ) are provided, which are assigned to different areas of the field of view, and the outputs of the light sensors or light-sensitive elements, each with one Threshold comparison device ( 14 , 50 ) are connected, the outputs of which are connected to a logic logic circuit ( 16 a, 16 b, 16 c), the logic circuit being connected to an actuating or switching device ( 9 ) through which the light emission of the Headlight is increased ( Fig. 7). 7. Headlamp arrangement according to claim 4, characterized in that a single light sensor is provided, the optics ( 2 ) of which a scanning device ( 37 , 38 ) is connected, through which various areas of the field of view in succession to a light-sensitive element ( 36 ) of the light sensor are mapped, and the output of the photosensitive element is connected to a circuit through which the output signals of the photosensitive element are fed to an evaluation circuit by the scanning device by the scanning device, which has a comparison device in which the output signals are connected to a Threshold value are compared, the output values of the comparison device being connected via a signal memory, in particular a logic logic circuit, to an actuating or switching device by means of which the light emission of the headlamp is increased. 8. Headlamp arrangement according to claim 4, characterized in that the field of view of several photosensitive elements one or multiple light sensors is mapped, the outputs of the light temp sensitive elements at the same time with a logical combination scarf device are connected via which a maximum value of the output signals of the individual photosensitive elements can be detected, which Maximum value is supplied to a threshold value comparison device, whose output signal controls an actuating or switching device, which increases the headlight's light emission. 9. Headlight arrangement according to one of claims 1 to 7, characterized characterized in that the actuating or switching device is arbitrary can be switched on and off. 10. Headlamp arrangement according to one of the preceding claims 4 to 8, characterized in that the actuating and switching device ( 9 ) via a timing element ( 47 ), which can be set by a first switching or egg NEN actuating process, for a predetermined time in the first switching or actuating position is held. 11. Headlight arrangement according to one of the preceding claims 4 to 9, characterized in that the actuating or Schaltvorrich device has a servomotor ( 54 ) through which an aperture ( 55 ) in the beam path of the headlamp can be switched or the position of the light source ( 58 ) is changeable. 12. Headlamp arrangement according to one of claims 4 to 9, characterized in that the actuating or switching device has a relay ( 17 ) through which the current flow to the light source ( 58 ) of the headlamp ( 57 ) can be switched on or off. 13. Headlamp arrangement according to claim 10, characterized in that the diaphragm ( 55 ) has a vertically extending diaphragm edge ( 61 ).